Tag Archives: microbes

When someone brings up the idea that life as we know it originated from space, it is easy to think they are crazy. However, instead of thinking of lanky-green aliens, would this idea seem so far fetched if they were talking about micro-organisms? There is a hypothesis called panspermia which hypothesizes that life originated elsewhere in space and migrated to Earth. This alien life would have arrived from another planet on a meteorite.

Comet Hale-Bopp courtesy kevindooley Flickr

There are three important stages a micro-organism would have to survive for a succussful journey. Must first survive take off, then space travel and finally survive the impact upon landing. There have been studies to evaluate the likelihood of surviving any of these phases.
Gerda Horneck from the German Aerospace Center stated in a paper which evaluated spore survival during space travel that, “There are certain areas at the rim of the impact crater, called the spallation zone, where by reflection of the shock wave the temperatures do not exceed 100 degrees Celsius.” This means that it’s cool enough for some spores to survive ejection from a planet.Rocco Mancinelli of the SETI Institute with his colleagues have published a review on bacteria surviving space journey. Their study supports that microbes could survive a trip through space. Micro-organisms hitching a ride on a meteorite can get protection from the dangerous UV radiation if they are below the surface.
A study published in 2001 explored the likelihood of bacterial spores surviving the landing impact. This study found that spores could survive impact scenarios that are similar to those that meteorites experience.

Micro-organism arriving from Mars seems the most likely since it is a relatively short journey. First it must be proven that there is or was life on Mars, a group of researchers from MIT are hoping to test Mars’ surface for microbes. If microbes are found, the next step would be to do DNA/RNA sequencing on them. With these tests we may be able to prove that our neighbouring planet may actually be our mother planet.

There is no definite answer to how life as we know it began on Earth. I found this research interesting because I never heard of this idea before. After looking at the papers concerning bacteria surviving space travel, I don’t think this idea is far fetched. I think it is a rather simple explanation to how Earth became inhabited. If Martian microbes could be sequenced and a connection was found between them and any organisms genome here on Earth, that would be incredible. I think it would be hard for many people to accept this idea because it makes our origins even more mysterious.

The Gulf of Mexico Oil Spill, also known as the BP Spill occurred on April 20, 2010 is known as the largest accidental marine oil spill in history[1]. The cleanup was done by burning the oil, and using chemical dispersant as well as oil-eating microbes. Microbes are small unicellular organisms. Alcanivorax borkumensis use oil as food[2]. By August 2010, most of the oil on the surface of the ocean was dissipated[3], but about 79% of the oil was still under the surface[4]. The BP (British Petroleum) compensation czar claimed that the Gulf would be recovered by 2012, however, research conducted by marine biologist Dr. Joye demonstrated that the oil is not degrading fast enough[5].

Joye’s research included 5 expeditions using deep-dives into the Gulf of Mexico near the oil spill to collect 250 samples from the ocean-floor and water columns. Her study found that much of the oil spill on the ocean floor and the water columns were from the BP spill. This was done by chemically fingerprinting the oil, and testing the samples in labs.

According to Joye’s findings, the oil-eating microbes that were thought to degrade most of the oil spill consumed about 10% of the oil spill. The rest are dispersed throughout the Gulf as small droplets, which can’t be seen on the surface, but a large amount of the oil droplets sank to the ocean-floor. Moreover, the mucous secretion from the oil-eating microbes which also contain oil sank to the bottom, on top of many bottom-dwelling sea creatures, such as starfish and crabs. Joye’s estimate of the total amount of oil leaked into the ocean is equivalent to 1.5 and 3 million barrels, and she thinks that the recovery will be much slower than what the BP czar claimed.

A wall of methane ice on the bottom of the Gulf of Mexico - Woods Hole Oceanographic Institution

The damage done by this accident propose a much long-term effect on the fragile marine ecosystem as well as the marsh in Louisiana. Before reading about Joye’s research, I used to believe that the oil spill was recovering fast, mostly by the oil-munching microbes. However, the pictures and the data collected from the bottom of the ocean by Joye changed my opinion, that under the turquoise-blue surface of the ocean, the sea-floor is still struggling to recover.

The long-term public health implications from this spill is unknown, and still needs to be studied.

An Interview with Dr. Samantha Joye at the UGA Oil Spill Symposium on 26th of January 2011: